This invention relates to systems and methods for delivering and deploying endovascular graft components within the vasculature of a patient.
It is well established that various fluid conducting body or corporeal lumens, such as veins and arteries, may deteriorate or suffer trauma so that repair is necessary. For example, various types of aneurysms or other deteriorative diseases may effect the ability of the lumen to conduct fluids and, in turn, may be life threatening. In some cases, the damage to the lumen is repairable only with the use of prosthesis such as an artificial vessel or graft.
For repair of vital lumens such as the aorta, surgical repair is significantly life threatening or subject to significant morbidity. Surgical techniques known in the art involve major surgery in which a graft resembling the natural vessel is spliced into the diseased or obstructed section of the natural vessel. Known procedures include surgically removing the damaged or diseased portion of the vessel and inserting an artificial or donor graft portion inserted and stitched to the ends of the vessel which were created by the removal of the diseased portion. More recently, devices have been developed for treating diseased vasculature through intraluminal repair. Rather than removing the diseased portion of the vasculature, the art has taught bypassing the diseased portion with a prosthesis and implanting the prosthesis within the vasculature. An intra arterial prosthesis of this type has two components: a flexible conduit, the graft, and the expandable framework, the stent (or stents). Such a prosthesis is called an endovascular graft.
It has been found that many abdominal aortic aneurysms extend to the aortic bifurcation. Accordingly, a majority of cases of endovascular aneurysm repair employ a graft having a bifurcated shape-with a trunk portion and two limbs, each limb extending into separate branches of vasculature. Currently available bifurcated endovascular grafts fall into two categories. One category of grafts are those in which a preformed graft is inserted whole into the arterial system and manipulated into position about the area to be treated. This is a unibody graft. The other category of endovascular grafts are those in which a graft is assembled in-situ from two or more endovascular graft components. This latter endovascular graft is referred to as a modular endovascular graft. Because a modular endovascular graft facilitates greater versatility of matching individual components to the dimensions of the patient's anatomy, the art has taught the use of modular endovascular grafts in order to minimize difficulties encountered with insertion of the devices into vasculature and sizing to the patient's vasculature.
Although the use of modular endovascular grafts minimize some of the difficulties, there are still drawbacks associated with the current methods of delivering and deploying these grafts. The drawbacks of current methods of delivery and deployment of endovascular graft components include delivery systems that are complicated to use and expensive to manufacture and difficulty in assembling the individual components in-situ.
Many delivery systems have three or more catheters coaxially disposed in order to provide adequate control over the endovascular graft and to facilitate inflating an expandable balloon as well as manipulating a release mechanism for deploying the graft. Such systems may be difficult for a single physician to use and, therefore, require additional personnel. The complexity of such delivery systems adds to the difficulty of use as well as the cost of production.
A lack of adequate healthy tissue near the aneurysm being treated provides difficulty with adequately anchoring the main body portion of a modular endovascular graft. If the aneurysm extends too close to the bifurcation of the vasculature, there may be a lack of healthy tissue to adequately anchor the limb support branches of the main body component. One method known in the art is to allow the limb support portions of the main body component to float freely in the aneurysm until limb components are delivered and deployed. However, this method presents difficulties with deploying the limb components of the modular endovascular graft within a main body component having limb support portions that are not anchored.
In a situation where an endovascular graft configured with superior and inferior anchoring devices is being employed to repair vasculature, it is often desirable to be able to deploy the superior anchoring device prior to deploying the inferior anchoring device. It is also often desirable to minimize the interference between the inferior anchoring device and other components of a delivery system. Although there has been some success in this area, there is nevertheless a need for a mechanism which effectively and consistently accomplishes these goals.
With regard to the method of delivery and deployment of endovascular graft components, there therefore exists a need for a endovascular graft delivery system that limits the number of components which must be manipulated, can be easily operated by a single technician without decreased reliability or additional risk to the patient, and facilitates control of graft deployment as well as control of a previously deployed main body component in order to deliver and deploy limb components therein. The devices and methods of the present invention addresses these and other needs.